Microsoft have released IE9 Platform Preview 3, an application that gives developers access to the IE9 rendering engine (it's not a full browser). In this update they have added hardware accelerated HTML5 Video, Canvas, Fonts (using WOFF) and big improvements in JavaScript with ES5, DOM Traversal, L2 and L3 events and 83/100 Acid3 score. It sits between Firefox and Chrome 6 on JavaScript speed, but outperforms every browser in real tests.

The problem is that Windows APIs are unique to Windows, and they don't use a common API (such as something similar to Canvas) that could accelerate all applications.

Therefore, each cross-platform application on Windows is required to write its own hardware-acceleration for rendering built in to the application, rather than it being available as a system-wide library to call.

There is a system-wide library to call, it's just not the same one that's available on Mac or on Linux, each of which have their own (multiple, in fact) system-wide libraries to call.

It's really unclear what you are asking for that isn't already present in Windows, and what you think Windows lacks that is somehow magically present elsewhere. Cross-platform apps that use normal widgets can use cross-platform toolkits like Qt... which already offers native hardware acceleration on a number of platforms. Or they can just use OpenGL directly.....

The reason Firefox and apps written in other toolkits don't already support hardware-accelerated rendering is as I understand it because they use low-level, CPU-based (not GPU-based) calls to figure out how to render stuff. There's really not a whole lot that can be done without some sort of rewrite.

There is a system-wide library to call, it's just not the same one that's available on Mac or on Linux, each of which have their own (multiple, in fact) system-wide libraries to call.

It's really unclear what you are asking for that isn't already present in Windows, and what you think Windows lacks that is somehow magically present elsewhere. Cross-platform apps that use normal widgets can use cross-platform toolkits like Qt... which already offers native hardware acceleration on a number of platforms. Or they can just use OpenGL directly.....

OpenGL is terrible on Windows. Utterly shocking performance.

Direct2D is Windows-only, and it is useless for any cross-platform applications.